O2 SIM only tariff upgrade £8 per month 30gb data.

I was on 20gb for £8 from a deal posted on here a couple of months ago, I checked to see how much the closest tariff was, more to see how lucky I was then expecting to find a better deal. But yeah! 30gb for £8, yet to see if my volt will take this up to 60gb but I'm expecting it will.

I used the app and went to the view or change your tarriff tab. Don't know if it works if you are going from any other tarrif.